CN110662517A

CN110662517A - Negative pressure wound therapy device

Info

Publication number: CN110662517A
Application number: CN201880034997.9A
Authority: CN
Inventors: 布莱恩·格林纳
Original assignee: Tj Smith & Internal Repair Co Ltd
Current assignee: Tj Smith & Internal Repair Co Ltd
Priority date: 2017-06-14
Filing date: 2018-06-11
Publication date: 2020-01-07
Anticipated expiration: 2038-06-11
Also published as: CA3065380A1; AU2018285235B2; AU2018285235A8; JP2020523060A; US20230065604A1; AU2018285235A1; US11471333B2; CN110662517B; US20200107965A1; EP3638167B1; EP3638167A1; WO2018229008A1; JP7155162B2

Abstract

The disclosed embodiments relate to devices and methods for wound therapy. In certain embodiments, the negative pressure wound therapy device may include a wound dressing having a spacer layer separated from an absorbent layer by an intermediate layer or drape. The wound dressing may include a first portion including a wound or tissue contacting layer, a first spacer layer, and a first backing layer including a first aperture. A spacer layer may be positioned between the contact layer and the first backing layer. The dressing may have a second portion including an intermediate drape with a second aperture, an absorbent layer, and a second backing layer. An absorbent layer is positioned between the intermediate drape and the second backing layer. The first and second apertures are configured to seal and allow fluid communication between the first and second portions of the wound dressing.

Description

Negative pressure wound therapy device

Cross Reference to Related Applications

This application claims priority from us provisional patent application No. 62/519762 filed on 14/6/2017, which is incorporated herein by reference in its entirety and made a part of the present disclosure.

Background

Technical Field

Various embodiments described herein relate to apparatuses, systems, and methods of treating wounds (e.g., treating wounds using a dressing in combination with negative pressure wound therapy).

Background

It is well known in the art to treat open or chronic wounds that are too large to spontaneously close or otherwise fail to heal by applying negative pressure to the wound site. Negative Pressure Wound Therapy (NPWT) systems currently known in the art typically involve placing a cover that is impermeable or semi-permeable to fluids over the wound, sealing the cover to the patient tissue surrounding the wound using various means, and connecting a source of negative pressure (e.g., a vacuum pump) to the cover in a manner that causes negative pressure to be created and maintained under the cover. It is believed that such negative pressure promotes wound healing by promoting the formation of granulation tissue at the wound site and assisting the body's normal inflammatory process while removing excess fluid that may contain adverse cytokines and/or bacteria. However, further improvements in NPWT are needed to fully realize therapeutic benefits.

Many different types of wound dressings are known for assisting NPWT systems. These different types of wound dressings include many different types of materials and layers, for example, gauze, pads, foam pads, or multi-layer wound dressings. One example of a multilayer wound dressing is the PICO dressing available from schlenght (Smith & Nephew) that includes a superabsorbent layer under a backing layer to provide a can-less system for treating wounds with NPWT. The wound dressing may be sealed to a suction port that provides a connection to a length of tubing that may be used to pump fluid out of the dressing and/or to transfer negative pressure from the pump to the wound dressing.

Wound dressings for negative pressure may have difficulty conforming to the contours of a patient's body. The inability to conform to the contours of the body area may be due to the use of rigid materials, including some absorbent materials, in the dressing. In some instances, it may be desirable to provide a conformable lower wound dressing member that includes a layer of material that is capable of conforming to a patient.

Disclosure of Invention

Embodiments of the present disclosure relate to apparatuses and methods for wound therapy. Some of the wound treatment devices described herein include a negative pressure source or pump system for providing negative pressure to the wound. The wound therapy device may also include wound dressings that may be used in conjunction with the negative pressure source and pump assembly described herein.

In some aspects, the negative pressure wound therapy device may comprise a wound dressing. The wound dressing may include a first dressing portion and a second dressing portion overlying the first dressing portion, the first dressing portion may include a tissue contacting layer configured to be positioned in contact with the wound and/or skin surrounding the wound, wherein the tissue contacting layer includes a first boundary portion at a perimeter of the tissue contacting layer, a first spacing layer, and a first backing layer including a first aperture, wherein the first backing layer includes a second boundary portion at a perimeter of the first backing layer, wherein the spacing layer is positioned between the tissue contacting layer and the first backing layer, and the first boundary portion of the tissue contacting layer is sealed to the second boundary portion of the first backing layer; and the second dressing portion may comprise an intermediate drape having a second aperture, wherein the intermediate drape comprises a third boundary portion at a perimeter of the intermediate drape, an absorbent layer, and a second backing layer comprising a fourth boundary portion at a perimeter of the second backing layer, wherein the absorbent layer is located between the intermediate drape and the second backing layer, and the third boundary portion of the intermediate drape is sealed to the fourth boundary portion of the second backing layer, and wherein the second dressing portion is attached to the first dressing portion such that the first aperture and the second aperture are fluidly connected, and wherein the second boundary portion of the first backing layer is unattached to the third boundary portion of the intermediate drape.

The apparatus of the preceding paragraph can also include any combination of the following features described in this paragraph, as well as other features described herein. In some embodiments, the apparatus can further comprise a suction port attached to the second backing layer over the third aperture in the second backing layer. In some embodiments, the apparatus may further comprise a filter configured to prevent or inhibit liquid from entering the suction port. In some embodiments, the apparatus may further comprise a source of negative pressure configured to apply negative pressure through the third aperture in the second backing layer, wherein the first, second, and third apertures are in fluid communication with one another and configured to provide fluid communication between the source of negative pressure and the wound. In some embodiments, the first spacer layer may comprise foam. In some embodiments, the absorber layer can include a superabsorbent material. In some embodiments, the apparatus may further include a second spacer layer, wherein the second spacer layer is positioned between the absorbent layer and the intermediate drape. In some embodiments, the second spacer layer may comprise a 3D fabric. In some embodiments, the first backing layer may comprise a flexible material or an additional material configured to allow the first backing material to bend. In some embodiments, the first spacing layer may include a plurality of slits. In some embodiments, the apparatus may further include a through-hole extending through the absorber layer. In some embodiments, the through-hole can be aligned below a suction port attached to the second backing layer. In some embodiments, the second backing layer may comprise a moisture vapor permeable material. In some embodiments, the tissue contacting layer, the first backing layer, the intermediate drape, and the second backing layer may all have substantially the same perimeter size and shape. In some embodiments, the first backing layer may be configured to attach to the intermediate drape at an area around the first aperture and an area around the second aperture. In some embodiments, the first spacer layer may have a smaller perimeter dimension than the tissue contacting layer and the first backing layer. In some embodiments, the first spacer layer may have a rectangular shape, a rounded rectangular shape, a racetrack shape, an oval shape, a circular shape, a triangular shape, or an irregular shape. In some embodiments, the third aperture in the second backing layer may be located at a central region of the second backing layer. In some embodiments, the third aperture in the second backing layer may be located at an edge region of the second backing layer. In some embodiments, the third aperture in the second backing layer may be located at a corner of the second backing layer. In some embodiments, the tissue contacting layer may extend through the entire area under the first backing layer. In some embodiments, the tissue contacting layer may include apertures, pores, or perforations to enable fluid flow through the tissue contacting layer.

In some aspects, a method of treating a wound with a negative pressure wound therapy device can include positioning a wound dressing over the wound, the wound dressing can include a first portion and a second portion, the first portion including a tissue contact layer configured to be positioned in contact with the wound and/or skin surrounding the wound, wherein the tissue contact layer includes a first boundary portion at a perimeter of the tissue contact layer, a first spacer layer, and a first backing layer including a first aperture, wherein the first backing layer includes a second boundary portion at a perimeter of the first backing layer, wherein the spacer layer is positioned between the tissue contact layer and the first backing layer, and the first boundary portion of the tissue contact layer is sealed to the second boundary portion of the first backing layer, and the second dressing portion includes an intermediate drape including a second aperture, wherein the intermediate drape includes a third boundary portion at a perimeter of the intermediate drape, An absorbent layer and a second backing layer, the second backing layer including a fourth boundary portion at a perimeter of the second backing layer, wherein the absorbent layer is positioned between the intermediate drape and the second backing layer, and the third boundary portion of the intermediate drape is sealed to the fourth boundary portion of the second backing layer, wherein the second dressing portion is attached to the first dressing portion such that the first aperture and the second aperture are fluidly connected, and wherein the second boundary portion of the first backing layer is unattached to the third boundary portion of the intermediate drape and negative pressure is applied through a third aperture in the cover layer, wherein the first, second, and third apertures provide fluid communication between a source of negative pressure and the wound.

Any features, components, or details of any arrangement or embodiment disclosed in the present application, including but not limited to any pump embodiment and any negative pressure wound therapy embodiment disclosed below, may be interchangeably combined with any other feature, component, or detail of any arrangement or embodiment disclosed herein to form new arrangements and embodiments.

Drawings

Embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

fig. 1A illustrates one embodiment of a negative pressure wound therapy system using a flexible fluid connector and a wound dressing capable of absorbing and storing wound exudate;

fig. 1B illustrates one embodiment of a negative pressure wound therapy system using a flexible fluid connector and a wound dressing capable of absorbing and storing wound exudate;

fig. 2A illustrates one embodiment of a negative pressure wound therapy system using a flexible fluid connector and a wound dressing capable of absorbing and storing wound exudate;

FIG. 2B illustrates a cross-section of one embodiment of a fluid connector connected to a wound dressing;

3A-D illustrate use and application of an embodiment of a wound treatment system to a patient;

FIG. 4A illustrates a top view of an embodiment of a negative pressure wound therapy system employing a lower wound dressing member comprising a foam layer capable of conforming to a patient and an upper wound dressing member capable of absorbing and storing wound exudate;

FIG. 4B illustrates an embodiment of a negative pressure wound therapy system employing a lower wound dressing member comprising a foam layer capable of conforming to a patient, and an upper wound dressing member capable of absorbing and storing wound exudate;

FIG. 4C illustrates a cross-section of an embodiment of a negative pressure wound therapy system employing a lower wound dressing member comprising a foam layer capable of conforming to a patient, and an upper wound dressing member capable of absorbing and storing wound exudate;

5A-5G illustrate an embodiment of a negative pressure wound therapy system employing a lower wound dressing member comprising a foam layer capable of conforming to a patient, and an upper wound dressing member capable of absorbing and storing wound exudate; and

fig. 6A-6B illustrate an embodiment of a foam layer for a negative pressure wound therapy system.

Detailed Description

Embodiments disclosed herein relate to apparatus and methods for treating wounds at reduced pressure, including negative pressure sources and wound dressing components and apparatus. The devices and assemblies (if any) comprising the wound covering material and filler material are sometimes collectively referred to herein as dressings.

Preferred embodiments disclosed herein relate to wound therapy for the human or animal body. Thus, any reference herein to a wound may refer to a wound on a human or animal body, and any reference herein to a body may refer to a human or animal body. In addition to having its broad ordinary meaning, the term "wound" as used herein also includes any body part of a patient that can be treated using negative pressure. It should be understood that the term "wound" should be interpreted broadly and encompasses both open and closed wounds in which the skin is torn, cut or punctured or in which trauma causes contusion, or any other surface wound or other condition or defect on the skin of a patient or a wound that otherwise benefits from reduced pressure treatment. Thus, a wound is broadly defined as any damaged tissue area that may or may not produce fluid. Examples of such wounds include, but are not limited to, abdominal wounds or other large or incised wounds that result from either surgery, trauma, sternotomy, fasciotomy, or other conditions, dehiscent wounds, acute wounds, chronic wounds, subacute and dehiscent wounds, traumatic wounds, flap and skin grafts, lacerations, abrasions, contusions, burns, diabetic ulcers, pressure ulcers, stoma, surgical wounds, traumatic ulcers, venous ulcers, and the like.

Such wounds may be treated using negative pressure wound therapy, wherein reduced pressure or negative pressure may be applied to the wound to facilitate and promote healing of the wound. It will also be appreciated that the wound dressings and methods as described herein may be applied to other parts of the body and are not necessarily limited to wound therapy.

It should be understood that embodiments of the present disclosure are generally suitable for use in a topical negative pressure ("TNP") therapy system. Briefly, negative pressure wound therapy helps to close and heal "difficult to heal" wounds of various morphologies by reducing tissue edema, promoting blood flow and granulation tissue formation, removing excess exudate, and may reduce bacterial load (thereby reducing infection risk). In addition, the therapy allows the wound to be less disturbed, resulting in faster healing. TNP therapy systems can also assist in the healing of surgically closed wounds by removing fluid and by helping to stabilize the tissue in close proximity to the closure site. Additional beneficial uses of TNP therapy may be found in grafts and flaps where removal of excess fluid is important and where close proximity of the graft to the tissue is required to ensure tissue viability.

As used herein, a reduced or negative pressure level (such as-X mmHg) represents a pressure level relative to normal ambient atmospheric pressure, which may correspond to 760mmHg (or 1atm, 29.93inHg, 101.325kPa, 14.696psi, etc.). Therefore, the negative pressure value-X mmHg reflects an absolute pressure lower than 760mmHg by X mmHg, or in other words, reflects an absolute pressure (760-X) mmHg. Further, a negative pressure less than or equal to X mmHg corresponds to a pressure closer to atmospheric pressure (e.g., -40mmHg less than-60 mmHg). Negative pressures that are greater than or more than-X mmHg correspond to pressures that are further away from atmospheric pressure (e.g., -80mmHg is greater than-60 mmHg). In some embodiments, local ambient atmospheric pressure is used as a reference point, and such local atmospheric pressure may not necessarily be, for example, 760 mmHg.

The negative pressure of some embodiments of the present disclosure may range from about-80 mmHg, or from about-20 mmHg to-200 mmHg. It should be noted that these pressures are based on normal ambient atmospheric pressure (which may be 760 mmHg). Therefore, in practice, about 560mmHg would be about-200 mmHg. In some embodiments, the pressure range may be between about-40 mmHg and-150 mmHg. Alternatively, pressure ranges of up to-75 mmHg, up to-80 mmHg, or above-80 mmHg may be used. In still other embodiments, a pressure range of less than-75 mmHg may be used. Alternatively, the negative pressure device may supply a pressure range in excess of about-100 mmHg, or even-150 mmHg.

In some embodiments of the wound closure devices described herein, increased wound contraction may result in increased tissue expansion in the surrounding wound tissue. This effect may be enhanced by varying the force applied to the tissue (e.g., by varying the negative pressure applied to the wound over time), possibly in combination with increased tension applied to the wound via various embodiments of the wound closure device. In some embodiments, the negative pressure may change over time, for example using a sine wave, a square wave, and/or in synchronization with one or more patient physiological indicators (e.g., heart beat).

Embodiments of the wound dressing, wound therapy apparatus and methods described herein may also be used in combination with or in addition to those described below: united states patent application No. 12/744277 entitled "WOUND THERAPY," filed on 7/1/2010 on 9/20/2010, united states patent application No. 12/744,218 entitled "WOUND THERAPY," filed on 8/19/2014 on 9/20/2010, united states patent application No. 13/092,042 entitled "WOUND DRESSING AND METHOD OF USE", filed on 21/4/2011, and united states patent application No. 14/715 entitled "flui connector FOR WOUND THERAPY" filed on 18/2015, filed on 18/5/0339158, the disclosures OF which are incorporated herein by reference in their entirety, including principles related to WOUND DRESSING embodiments, WOUND components and DRESSINGs, and other materials used in WOUND DRESSINGs.

Furthermore, some embodiments relating to TNP wound therapy comprising a wound dressing in combination with a pump AND/or associated electronics as described herein are also combined with or supplemented with the use described in international application PCT/EP2016/059329 entitled "REDUCED PRESSURE APPARATUS AND METHODS" filed on day 3/11/2016 AND published as WO2016174048a1 in 2016, filed on day 26/4/2016.

Fig. 1A-B illustrate an embodiment of a negative pressure wound therapy system 10 using a wound dressing 100 in combination with a fluid connector 110. Here, the fluid connector 110 may include an elongated conduit, more preferably a bridge 120 having a proximal end 130 and a distal end 140, and an applicator 180 at the distal end 140 of the bridge 120. An optional link 160 is preferably provided at the proximal end 130 of the bridge 120. The cap 170 may be provided with a system (and in some cases may be attached to the coupler 160 as shown). The cap 170 may be used to prevent fluid from leaking out of the proximal end 130. The system 10 may include a source of negative pressure, such as a pump or negative pressure unit 150 capable of supplying negative pressure. The pump may include a canister or other container for storing wound exudate and other fluids that may be removed from the wound. The tank or container may also be provided separately from the pump. In some embodiments, as shown in FIGS. 1A-1B, pump 150 may be a tankless pump, such as a PICO sold by Schlenght^TMAnd (4) a pump. Pump 150 may be connected to coupling 160 via tube 190, or pump 150 may be connected directly to coupling 160 or directly to bridge 120. In use, the dressing 100 is placed over a suitably prepared wound, which in some cases may be filled with a wound packing material, such as foam or gauze. The applicator 180 of the fluid connector 110 has a sealing surface that is placed over the orifice of the dressing 100 and sealed to the top surface of the dressing 100. Pump 150 is connected to coupling 160 via tube 190, or directly to coupling 160 or bridge 120 before, during, or after fluid connector 110 is connected to dressing 100. The pump is then activated, thereby supplying negative pressure to the wound. Negative pressure may be applied until a desired level of wound healing is achieved. In some embodiments, the system may be miniaturized and portable, although larger conventional pumps may also be used with the dressing 100. In some embodiments, the pump may be attached or mounted on or near the dressing 100.

In some embodiments, the negative pressure source (e.g., pump) and some or all of the other components of the TNP system (e.g., power source, sensors, connectors, user interface components (e.g., buttons, switches, speakers, screens, etc.) are integrated with the wound-dressing. The wound dressing may include a cover layer for positioning over the wound dressing layer. The cover layer may be the uppermost layer of the dressing. In some embodiments, the wound dressing may include a second cover layer for positioning over the layers and any integrally bonded components of the wound dressing. The second cover layer may be the uppermost layer of the dressing or may be a separate envelope enclosing the integrally bonded components of the topical negative pressure system.

As shown in fig. 2A, the fluid connector 110 preferably includes an enlarged distal end, or head 140 in fluid communication with the dressing 100, as will be described in greater detail below. In one embodiment, the enlarged distal end is rounded or annular. The head 140 is shown here as being positioned near the edge of the dressing 100, but may be positioned at any location on the dressing. For example, some embodiments may provide a centered or off-centered position that is not on or near an edge or corner of the dressing 100. In some embodiments, dressing 100 may include two or more fluid connectors 110, each including one or more heads 140 in fluid communication therewith. In a preferred embodiment, the head 140 may measure 30mm along its widest edge. The head 140 forms at least a portion of the applicator 180 described above, which is configured to seal the top surface of the wound dressing.

Fig. 2B shows a cross-section through a WOUND dressing 100 similar to the WOUND dressing 100 shown in fig. 1B and described in international application number PCT/IB2013/001469, international application number PCT/IB2013/001469 filed 5/22 of 2013, published 28 of 2013 at 11/28 of WO2013/175306a2 entitled "apparatus FOR use in association with new WOUND PRESSURE THERAPY, the disclosure of which is hereby incorporated by reference in its entirety along with the fluid connector 110. Wound dressing 100 may alternatively be any combination of features of any wound dressing embodiment disclosed herein or any number of wound dressing embodiments disclosed herein, which may be positioned over a wound site to be treated. The dressing 100 may be placed so as to form a sealed cavity over the wound site. In a preferred embodiment, the dressing 100 includes a top or cover layer, or backing layer 220 attached to an optional wound contact layer 222, both of which are described in more detail below. The two

layers

220, 222 are preferably joined or sealed together to define an interior space or chamber. The interior space or chamber may include additional structure that may be adapted to distribute or transmit negative pressure, store wound exudate and other fluids removed from the wound, as well as other functions, which will be explained in more detail below. Examples of such structures described below include transfer layer 226 and absorber layer 221.

An upper, top or upper layer as used herein refers to the layer that is furthest from the skin or surface of the wound when the dressing is in use and positioned over the wound. Thus, a lower surface, layer, sub-layer or layer refers to the layer closest to the skin or surface of the wound when the dressing is in use and positioned over the wound.

As shown in fig. 2B, the wound contact layer 222 may be a polyurethane layer or a polyethylene layer or other flexible layer that is perforated, for example, via a hot-pin process, a laser ablation process, an ultrasonic process, or in some other manner, or otherwise made permeable to liquids and gases. Wound contact layer 222 has a lower surface 224 and an upper surface 223. Perforations 225 preferably include through-holes in wound contact layer 222 that allow fluid to flow through layer 222. Wound contact layer 222 helps prevent tissue ingrowth into the other materials of the wound dressing. Preferably, the perforations are small enough to meet this requirement while still allowing fluid to flow therethrough. For example, perforations formed as slits or holes having a size in the range of 0.025mm to 1.2mm are considered to be small enough to help prevent tissue ingrowth into the wound dressing while allowing wound exudate to flow into the dressing. In some configurations, the wound contact layer 222 can help maintain the integrity of the entire dressing 100 while also creating an airtight seal around the absorbent pad to maintain negative pressure at the wound site.

Some embodiments of wound contact layer 222 may also serve as a carrier for optional lower and upper adhesive layers (not shown). For example, the lower pressure sensitive adhesive may be provided on the lower surface 224 of the wound dressing 100, while the upper pressure sensitive adhesive layer may be provided on the upper surface 223 of the wound contact layer. The pressure sensitive adhesive may be a silicone, hot melt, hydrocolloid or acrylic based adhesive or other such adhesive, and may be formed on both sides of the wound contact layer, or alternatively on a selected one of the two sides of the wound contact layer, or not formed on both sides. The lower pressure sensitive adhesive layer, when used, may help adhere the wound dressing 100 to the skin surrounding the wound site. In some embodiments, the wound contact layer may comprise a perforated polyurethane film. The lower surface of the membrane may be provided with a silicone pressure sensitive adhesive and the upper surface may be provided with an acrylic pressure sensitive adhesive, which may help the dressing maintain its integrity. In some embodiments, the polyurethane film layer may be provided with adhesive layers on its upper and lower surfaces, and all three layers may be perforated together.

A layer 226 of porous material may be positioned over the wound contact layer 222. This porous or transmission layer 226 allows the transmission of fluids including liquids and gases away from the wound site into the upper layers of the wound dressing. In particular, the transmission layer 226 preferably ensures that the open air channel maintains the transmission of negative pressure over the wound area even when the absorbent layer absorbs large amounts of exudate. The layer 226 should preferably remain open at typical pressures that will be applied during negative pressure wound therapy as described above, so that the entire wound site is subjected to an equalized negative pressure. Layer 226 may be formed of a material having a three-dimensional structure. For example, a knitted or woven spacer fabric (e.g., Baltex 7970 weft knit polyester) or a non-woven fabric may be used.

In some embodiments, the transmission layer 226 comprises a 3D polyester spacer fabric layer comprising a top layer (that is, the layer that is distal to the wound bed in use) of 84/144 textured polyester, and a bottom layer (that is, the layer that is proximal to the wound bed in use) of 10 denier flat polyester, and a third layer sandwiched between the two layers, the third layer being an area defined by knitted polyester viscose, cellulose or similar monofilament fibers. Of course, other materials and other linear mass densities of fibers may be used.

Although reference is made throughout this disclosure to monofilament fibers, it should be understood that multiple strand alternatives may of course be used. Thus, the top spacer fabric has a greater number of filaments in the yarns used to form it than the number of filaments that make up the yarns used to form the bottom spacer fabric layer.

This difference between the number of filaments in the spaced apart layers helps to control the flow of moisture through the transfer layer. In particular, by having a greater number of filaments in the top layer, i.e., the top layer is made of yarns having more filaments than the yarns used for the bottom layer, liquid tends to wick more along the top layer than the bottom layer. In use, this difference tends to wick liquid away from the wound bed and into the central region of the dressing where the absorbent layer 221 helps to lock the liquid away or wick the liquid forward on itself towards the liquid transpirable cover layer.

Preferably, to improve the flow of liquid through the transfer layer 226 (that is, perpendicular to the channel regions formed between the top and bottom spacer layers), the 3D fabric may be treated with a dry cleaning agent (such as, but not limited to, perchloroethylene) to help remove any manufactured products, such as the previously used mineral oils, fats, and/or waxes, which may interfere with the hydrophilic ability of the transfer layer. In some embodiments, an additional manufacturing step may then be performed in which the 3D spacer fabric is washed in a hydrophilic agent (such as, but not limited to, Feran Ice30g/l available from Rudolph Group). This process step helps to ensure that the surface tension on the material is very low so that liquids such as water can enter the 3D knitted fabric once they contact the fabric. This also helps to control the flow of the liquid fouling component of any exudate.

The absorbing material layer 221 is disposed over the transmission layer 226. Absorbent materials, including foams or non-woven natural or synthetic materials, and optionally super-absorbent materials, form reservoirs for fluids (particularly liquids) removed from the wound site. In some embodiments, the layer 10 may also help absorb fluids toward the backing layer 220.

The material of the absorbent layer 221 may also prevent liquids collected in the wound dressing 100 from freely flowing within the dressing and preferably acts so as to contain any liquids collected within the dressing. Absorbent layer 221 also helps distribute fluid throughout the layer via wicking for fluid absorption from the wound site and storage throughout the absorbent layer. This helps to prevent accumulation in the region of the absorber layer. The capacity of the absorbent material must be sufficient to manage the exudate flow rate of the wound when negative pressure is applied. Since, in use, the absorbent layer is subjected to a negative pressure, the material of the absorbent layer is selected to absorb liquid in this case. There is a possibility of absorbing liquid under negative pressureSuch as superabsorbent materials. Absorber layer 221 may be generally formed of ALLEVYN^TMFoam, Freudenberg 114-^TM11C-450. In some embodiments, the absorbent layer 221 can include a composite including a superabsorbent powder, a fibrous material, such as cellulose, and a binding fiber. In a preferred embodiment, the composite is an air-laid thermal bond composite.

In some embodiments, the absorbent layer 221 is a layer of non-woven cellulose fibers having superabsorbent material in the form of dry particles dispersed throughout. The use of cellulose fibers introduces a fast wicking element that helps to rapidly and uniformly distribute the liquid absorbed by the dressing. The juxtaposition of the multi-strand fibers results in a strong capillary action in the fiber mat, which helps to distribute the liquid. In this way, the superabsorbent material is effectively supplied with liquid. Wicking also helps to bring liquid into contact with the overlying layer to help increase the transpiration rate of the dressing.

An aperture, hole, or aperture 227 is preferably provided in the backing layer 220 to allow negative pressure to be applied to the dressing 100. The fluid connector 110 is preferably attached or sealed to the top of the backing layer 220 over the aperture 227 created in the dressing 100 and transmits negative pressure through the aperture 227. A length of tubing may be coupled at a first end to the fluid connector 110 and at a second end to a pump unit (not shown) to allow fluid to be pumped out of the dressing. Where the fluid connector is adhered to the top layer of the wound dressing, a length of tubing may be coupled at the first end of the fluid connector such that the tubing or conduit extends parallel or substantially to the top surface of the dressing away from the fluid connector. The fluid connector 110 may be adhered and sealed to the backing layer 220 using an adhesive, such as acrylic, cyanoacrylate, epoxy, UV curable, or hot melt adhesive. The fluid connector 110 may be formed from a soft polymer, such as polyethylene, polyvinyl chloride, silicone, or polyurethane, having a shore a durometer of 30 to 90. In some embodiments, the fluid connector 110 may be made of a soft or conformable material.

Preferably, the absorbent layer 221 includes at least one through hole 228 positioned so as to underlie the fluid connector 110. In some embodiments, the through-hole 228 may be the same size as the opening 227 in the backing layer, or may be larger or smaller. As shown in fig. 2B, a single through-hole may be used to create an opening located below the fluid connector 110. It will be appreciated that a plurality of openings may alternatively be used. Additionally, if more than one port is used according to certain embodiments of the present disclosure, one or more openings may be created in the absorbent layer in registration with each respective fluid connector. Although not necessary for certain embodiments of the present disclosure, the use of through holes in the superabsorbent layer may provide a fluid flow path that remains unobstructed, particularly when the absorbent layer is near saturation.

As shown in fig. 2B, an aperture or via 228 is preferably provided in the absorber layer 221 below the aperture 227, such that the aperture is directly connected to the transmission layer 226. This allows negative pressure applied to the fluid connector 110 to communicate with the transmission layer 226 without passing through the absorbent layer 221. This ensures that the negative pressure applied to the wound site is not inhibited by the absorbent layer when the absorbent layer absorbs wound exudate. In other embodiments, no apertures may be provided in the absorber layer 221, or a plurality of apertures may be provided below the aperture 227. In other alternative embodiments, an additional layer (e.g., another transmission layer or a masking layer as described in U.S. patent application No. 14/418874 entitled "bound DRESSING anode method OF tree maintenance," filed on day 2015 7, 9, published as US 2015/0190286a1, filed on day 2015 1, 30, incorporated herein by reference in its entirety) may be disposed above the absorber layer 221 and below the backing layer 220.

The backing layer 220 is preferably impermeable to gases, but permeable to water vapor, and may extend across the width of the wound dressing 100. The backing layer 220, which may be, for example, a polyurethane film (e.g., Elastollan SP9109) having a pressure sensitive adhesive on one side, is air impermeable, and this layer thus serves to cover the wound and seal the wound cavity on which the wound dressing is placed. In this way, an effective chamber is created between the backing layer 220 and the wound site, in which chamber a negative pressure can be created. For example, the backing layer 220 may be sealed to the wound contact layer 222, preferably in a border area around the circumference of the dressing, by adhesive or welding techniques, ensuring that no air is drawn through the border area. The backing layer 220 protects the wound from external bacterial contamination (bacterial barrier) and allows liquid from wound exudate to be transported through this layer and evaporate from the outer surface of the film. The backing layer 220 preferably comprises two layers; a polyurethane film and an adhesive pattern coated on the film. The polyurethane film is preferably permeable to water vapor and may be made of a material that has an increased permeability to water when wetted. In some embodiments, the water vapor permeability of the backing layer increases when the backing layer becomes wet. The moisture permeability of the wet back liner may be up to about ten times greater than the moisture permeability of the dry back liner.

The absorbent layer 221 may have an area larger than the transmission layer 226 such that the absorbent layer covers the edges of the transmission layer 226, thereby ensuring that the transmission layer does not contact the backing layer 220. This provides an outer channel of the absorbent layer 221 which is in direct contact with the wound contact layer 222, which facilitates a faster absorption of exudate into the absorbent layer. In addition, the external channel ensures that no liquid can pool around the circumference of the wound cavity, which may penetrate the seal around the periphery of the dressing, resulting in the formation of leaks. As shown in fig. 2A-2B, the absorbent layer 221 may define a perimeter that is smaller than the backing layer 220 such that a boundary or border region is defined between an edge of the absorbent layer 221 and an edge of the backing layer 220.

As shown in fig. 2B, one embodiment of the wound dressing 100 includes an orifice 228 in the absorbent layer 221 below the fluid connector 110. In use, for example when negative pressure is applied to the dressing 100, the wound facing portion of the fluid connector may thus be in contact with the transmission layer 226, which may thus facilitate transmission of negative pressure to the wound site even when the absorbent layer 221 is filled with wound fluid. Some embodiments may have the backing layer 220 at least partially adhered to the transmission layer 226. In some embodiments, the aperture 228 is at least 1-2mm larger than the diameter of the wound facing portion or aperture 227 of the fluid connector 110.

Particularly for embodiments having a single fluid connector 110 and through-hole, it may be preferred that the fluid connector 110 and through-hole are located in an off-center position as shown in fig. 2A. Such a position may allow the dressing 100 to be positioned on a patient such that the fluid connector 110 is elevated relative to the rest of the dressing 100. So positioned, the fluid connector 110 and filter 214 (described below) are less likely to come into contact with wound fluid that may prematurely occlude the filter 214, such that transmission of negative pressure to the wound site is impaired.

Turning now to fluid connector 110, a preferred embodiment includes a sealing surface 216, a bridge 211 (corresponding to bridge 120 in fig. 1A-1B) having a proximal end 130 and a distal end 140, and a filter 214. The sealing surface 216 preferably forms an applicator as previously described that is sealed to the top surface of the wound dressing. In some embodiments, the bottom layer of the fluid connector 110 may include a sealing surface 216. The fluid connector 110 may also include an upper surface that is vertically spaced from the sealing surface 216, which in some embodiments is defined by a separate upper layer of the fluid connector. In other embodiments, the upper and lower surfaces may be formed from the same piece of material. In some embodiments, the sealing surface 216 may include at least one aperture 229 therein to communicate with the wound dressing. In some embodiments, the filter 214 may be positioned through the opening 229 in the sealing surface, and may span the entire opening 229. The sealing surface 216 may be configured to seal the fluid connector to a cover layer of a wound dressing and may include an adhesive or a weld. In some embodiments, the sealing surface 216 may be placed over an aperture in the cover layer. In other embodiments, the sealing surface 216 may be positioned over apertures in the cover layer and apertures in the absorbent layer 220 to allow the fluid connector 110 to provide air flow through the transmission layer 226. In some embodiments, the bridge 211 can include a first fluid passage 212 in communication with a negative pressure source, the first fluid passage 212 including a porous material, e.g., a 3D knitted material, which can be the same as or different from the porous layer 226 described previously. The bridge 211 is preferably encapsulated by at least one

flexible membrane layer

208, 210 having a proximal end and a distal end, and is configured to surround the first fluid passageway 212, the distal end of the flexible membrane connecting the sealing surface 216. The filter 214 is configured to substantially prevent wound exudate from entering the bridge.

Some embodiments may also include an optional second fluid passageway positioned above the first fluid passageway 212. FOR example, some embodiments may provide an air leak port, which may be disposed at the proximal end of the top layer 208, configured to provide an air path into the first fluid pathway 212 and the dressing 100, similar to the suction adapter described in U.S. patent No. 8,801,685 entitled "apparatus and methods FOR use in connection with pressurized dressing manufacture" filed 30/12.2011, the disclosure of which is incorporated herein by reference in its entirety.

Preferably, the fluid passageways 212 are constructed of a compliant material that is flexible and also allows fluid to pass therethrough if the spacers kink or fold. Suitable materials for the fluid pathway 212 include, without limitation, foams, including open foams, such as polyethylene or polyurethane foams, meshes, 3D knitted fabrics, nonwovens, and fluid channels. In some embodiments, the fluid passage 212 may be constructed of materials similar to those described above with respect to the transmission layer 226. Advantageously, such materials used in the fluid pathway 212 not only allow for greater patient comfort, but also provide greater kink resistance so that the fluid pathway 212 is still able to transport fluid from the wound toward the negative pressure source when kinked or bent.

In some embodiments, the fluid pathway 212 may be formed of a wicking fabric, such as a knitted or woven spacer fabric (e.g., knitted polyester 3D fabric, Baltex

Or Gehring

) Or a nonwoven fabric. These materials are preferably selected to be suitable for channeling wound exudate away from the wound and for transmitting negative pressure and/or exhaust air to the wound site, and may also impart a degree of kink or occlusion resistance to the fluid pathway 212. In some embodiments, the wicking fabric may have a three-dimensional structure, which in some cases may help wick fluid or transmit negative pressure. In certain embodiments including wicking fabrics, these materials remain open and are capable of transmitting negative pressure to the wound area at pressures typical for use in negative pressure therapy (e.g., between 40 and 150 mmHg). In some embodiments, the wicking fabric may comprise a stack or laminateSeveral layers of material on each other that may be used in some cases to prevent the fluid passageway 212 from collapsing under the application of negative pressure. In other embodiments, the wicking fabric used in the fluid pathway 212 may be between 1.5mm to 6 mm; more preferably, the wicking fabric may be 3mm to 6mm thick and may comprise one or several separate layers of wicking fabric. In other embodiments, the fluid passage 212 may be 1.2 to 3mm thick, and preferably thicker than 1.5 mm. Some embodiments (e.g., a suction adapter for a dressing holding a liquid such as wound exudate) may use a hydrophobic layer in the fluid pathway 212, and only gas may travel through the fluid pathway 212. Furthermore, and as previously mentioned, the materials used in the system are preferably conformable and soft, which may help avoid pressure sores and other complications that may be caused by the wound treatment system pressing against the patient's skin.

Preferably, the filter element 214 is liquid impermeable, but breathable, and is provided to act as a liquid barrier and ensure that no liquid can escape from the wound dressing 100. The filter element 214 may also act as a bacterial barrier. Typically, the pore size is 0.2 μm. Suitable materials for the filter material of the filter element 214 include 0.2 micron Gore from the MMT series^TMExpanded PTFE, PALL Versapore^TM200R and Donaldson^TMTX 6628. Larger pore sizes may also be used, but these may require a secondary filtration layer to ensure complete bioburden containment. Since the wound fluid contains liquid, it is preferred, but not necessary, to use an oleophobic filter membrane, e.g., 1.0 micron MMT-332, before 0.2 micron MMT-323. This prevents the lipid from clogging the hydrophobic filter. The filter element may be attached or sealed to the port and/or cover membrane over the aperture. For example, the filter element 214 may be molded into the fluid connector 110, or may be adhered to one or both of the top of the cover layer and the bottom of the suction adapter 110 using an adhesive, such as, but not limited to, a UV cured adhesive.

It should be understood that other types of materials may be used for the filter element 214. More generally, microporous films, which are thin flat sheets of polymeric material containing billions of micropores, can be used. Depending on the membrane selected, these pores may range in size from 0.01 to greater than 10 microns. Microporous membranes have both hydrophilic (drainage) and hydrophobic (waterproofing) forms. In some embodiments of the present invention, the filter element 214 comprises a support layer and an acrylic copolymer film formed on the support layer. Preferably, the wound dressing 100 according to certain embodiments of the present invention uses a Microporous Hydrophobic Membrane (MHM). Many polymers can be used to form MHMs. For example, the MHM may be formed from one or more of PTFE, polypropylene, PVDF, and acrylic copolymers. All of these optional polymers may be treated to obtain specific surface characteristics that may be hydrophobic and oleophobic. Thus, these will reject liquids with low surface tension, such as multi-vitamin infusions, lipids, surfactants, oils and organic solvents.

The MHM blocks liquid while allowing air to flow through the membrane. They are also highly efficient air filters that eliminate potentially infectious aerosols or particles. It is well known that a single piece MHM is an alternative to mechanical valves or vents. Accordingly, configuring the MHM may reduce product assembly costs to improve patient profits and cost/benefit ratios.

The filter element 214 may also include an odor absorbing material such as activated carbon, carbon fiber cloth, or Vitec Carbotec-RT Q2003073 foam, among others. For example, the odor absorbing material may form a layer of the filter element 214, or may be sandwiched between microporous hydrophobic membranes of the filter element. The filter element 214 thus allows gas to vent through the pores. However, the dressing contains liquids, particles and pathogens.

Similar to the embodiments of the wound dressings described above, some wound dressings include a perforated wound contact layer having a silicone adhesive on the skin-contacting side and an acrylic adhesive on the back side. A transmission layer or 3D spacer fabric mat is located above the boundary layer. An absorber layer is positioned over the transfer layer. The absorbent layer may comprise a super absorbent Nonwoven (NW) mat. The absorbent layer may be about 5mm across the transfer layer at the perimeter. The absorbent layer may have an aperture or through hole towards one end. The orifice may be about 10mm in diameter. The backing layer is positioned over the transmission layer and the absorbent layer. The backing layer may be a high Moisture Vapor Transmission Rate (MVTR) film coated with a pattern of acrylic adhesive. The high MVTR film and wound contact layer encapsulate the transmission layer and absorbent layer, creating a peripheral boundary of about 20 mm. The backing layer may have a 10mm orifice overlying the orifice in the absorbent layer. A fluid connector may be attached over the well, the fluid connector including a liquid impermeable, gas permeable semi-permeable membrane (SPM) overlying the orifice.

In some embodiments, a negative pressure source (e.g., a pump) and some or all of the other components of the local negative pressure system, such as a power source, sensors, connectors, user interface components (e.g., buttons, switches, speakers, screens, etc.), etc., may be integral with the wound dressing. In some embodiments, the components may be integrated below, within, on top of, and/or near the backing layer. In some embodiments, the wound dressing may include a second cover layer and/or a second filtration layer for positioning over the layers and any integrated components of the wound dressing. The second cover layer may be the uppermost layer of the dressing or may be a separate envelope enclosing the integrated components of the local negative pressure system.

Figures 3A-3D illustrate the use of one embodiment of a negative pressure therapy wound therapy system for treating a wound site on a patient. Fig. 3A shows a wound site 1000 cleaned and prepared for treatment. Here, it is preferable to clean healthy skin around the wound site 1000 and remove or scrape off superfluous hair. The wound site 1000 may also be irrigated with a sterile saline solution if desired. Alternatively, the skin protectant may be applied to the skin surrounding the wound site 1000. If desired, a wound packing material such as foam or gauze may be placed in the wound site 1000. This may be preferred if the wound site 1000 is a deeper wound.

After the skin surrounding the wound site 1000 is dry, and referring now to fig. 3B, a wound dressing 1100 may be positioned and placed over the wound site 1000. Preferably, wound dressing 1100 is placed over and/or in contact with wound site 1000 with a wound contact layer. In some embodiments, an adhesive layer is provided on the lower surface of the wound contact layer, which in some cases may be protected by an optional release layer for removal prior to placement of wound dressing 1100 over wound site 1000. Preferably, the dressing 1100 is positioned such that the fluid connector 1110 is in an elevated position relative to the rest of the dressing 1100, so as to avoid pooling of fluid around the port. In some embodiments, dressing 1100 is positioned so that fluid connector 1110 does not directly overlie the wound, and is flush with or at a point above the wound. To facilitate adequate sealing of the TNP, the edges of the dressing 1100 are preferably smooth to avoid wrinkles or folds.

Referring now to fig. 3C, dressing 1100 is connected to pump 1150. The pump 1150 is configured to apply negative pressure to the wound site via the dressing 1100, and typically through a conduit. In some embodiments, and as described herein, the fluid connector 1110 can be used to join the conduit 1190 from the pump 1150 to the dressing 1100. When the fluid connector is adhered to the top layer of the wound dressing, a length of tubing may be coupled at the first end of the fluid connector such that the tubing or conduit extends away from the fluid connector parallel to the top of the dressing. In some embodiments, the catheter may include a fluid connector. It is expressly contemplated that the conduit may be a flexible bridge, a rigid tube, or any other device that may be used to convey a fluid. Upon application of negative pressure with pump 1150, dressing 1100 may partially collapse in some embodiments and assume a wrinkled appearance due to evacuation of some or all of the air under dressing 1100. In some embodiments, the pump 1150 may be configured to detect whether any leaks are present in the dressing 1100, such as at the interface between the dressing 1100 and the skin surrounding the wound site 1000. If a leak is found, it is preferred to remedy the leak before continuing the treatment.

Turning to fig. 3D, additional securing strips 1010 may also be attached around the edges of the dressing 1100. Such a fixation strip 1010 may be advantageous in some situations in order to provide additional sealing against the patient's skin around the wound site 1000. For example, the fixation bar 1010 may provide additional sealing when the patient is more active. In some cases, particularly if dressing 1100 is placed in a difficult to reach or contoured area, securing bar 1010 may be used prior to activating pump 1150.

Treatment of wound site 1000 preferably continues until the wound reaches a desired level of healing. In some embodiments, it may be desirable to replace the dressing 1100 after a certain period of time has elapsed, or if the dressing is full of wound fluid. During this replacement, the pump 1150 may be maintained and only the dressing 1100 replaced.

Fig. 4A shows a top view of an embodiment of a negative pressure wound therapy system employing a lower wound dressing member 450 comprising a conformable manifold system, and an upper wound dressing member 460 capable of absorbing and storing wound exudate. The negative pressure wound dressing illustrated in fig. 4A includes a wound dressing similar to the wound dressing described with reference to fig. 1A-1B and 2A-2B, but the wound dressing includes additional layers that form a lower wound dressing component 450, including a conformable manifold system. In some embodiments, the lower wound dressing member 450 may be positioned below the wound dressing member described with reference to fig. 1A-1B and 2A-2B. The wound dressing shown in fig. 4A includes an upper wound dressing component 460 that includes a wound cover layer or top backing layer 420 and an absorbent layer 421, which are similar to the components described with reference to fig. 1A-1B and 2A-2B. The upper wound dressing component may also include an intermediate drape (not shown) below the absorbent layer. A border or perimeter portion of the intermediate drape may be sealed to the top backing layer at the perimeter of the top backing layer. As described herein, the intermediate drape may include an aperture to provide fluid communication with a conformable system 450 positioned between the intermediate drape and the wound.

Fig. 4B-4C illustrate layers of an embodiment of the negative pressure wound therapy system of fig. 4A employing a lower wound dressing member 450 comprising a conformable manifold system and an upper wound dressing member 460 capable of absorbing and storing wound exudate.

As shown in fig. 4B-4C, wound dressing 400 may include: an upper wound dressing member 460 comprising an absorbent material, and a lower wound dressing member 450 comprising a conformable manifold. Lower wound dressing component 450 may include lower wound contact layer 425, conformable manifold or foam layer 424, and first backing layer 423. Lower wound contact layer 425 may be similar to wound contact layer 222 described with reference to fig. 2B, and may be placed in contact with a wound. As used herein, wound contact layer and tissue contact layer are used interchangeably. The conformable manifold may include a foam layer 424. In some embodiments, the foam layer comprises a rectangle, a rounded rectangle, a racetrack, an oval, a circle, a triangle, or an irregular shape with different angles and different side dimensions. The foam layer may have a smaller perimeter dimension than the tissue contacting layer. Foam layer 424 may include reticulated foam and/or other foam, padding, transmission or spacing layers known in the art. In some embodiments, the conformable manifold may comprise 30ppi of reticulated foam. In some embodiments, the conformable manifold may comprise 6mm 30ppi of reticulated foam. As described herein, a conformable manifold may include foam and/or other spacing or transmission layers. The terms foam, spacing, and/or transmission layer as used herein are used interchangeably to refer to a layer of material in a dressing configured to distribute negative pressure throughout a wound area. The first backing layer 423 can be a moisture vapor permeable film similar to the covering or backing layers described with reference to fig. 2B. In other embodiments, the first backing layer 423 can be a non-permeable film. In some embodiments, the first backing layer 423 can be another material that is both liquid and gas impermeable. In some embodiments, wound contact layer 425 extends across the entire area under first backing layer 423. In some embodiments, the wound contact layer and the first backing layer may have substantially the same perimeter size and shape. The foam layer may have a perimeter dimension that is smaller than the wound contact layer and the first backing layer. The perimeter of first backing layer 423 may be sealed to encapsulate and cover the outer perimeter of lower wound contact layer 425 of foam layer 424. First backing layer 423 may include an aperture or opening 451 in first backing layer 423. As shown in fig. 4B, an aperture or opening 451 can be positioned in a central portion of first backing layer 423.

The lower wound dressing member 450 may be used in conjunction with an upper wound dressing member 460 that includes an absorbent material similar to that described with reference to fig. 2B. The wound dressing system may include an intermediate drape 422 provided over the first backing layer. The intermediate drape 422 may include an aperture or opening 452. In some embodiments, the aperture or opening 452 may be positioned in a central portion of the intermediate drape 422. Aperture 452 may be aligned with and sealed to aperture 451 of first backing layer 423. In some embodiments, the area surrounding the first aperture may be sealed to the area surrounding the second aperture to attach the first backing layer to the intermediate drape.

Apertures

451 and 452 may provide fluid communication between the two layers.

As shown in fig. 4B and 4C, an absorbent layer 421 may be disposed over the intermediate drape 422. Absorber layer 421 may be similar to absorber material 221 described with reference to fig. 2B. A second backing layer 420 can be disposed over the absorbent layer 421. The second backing layer 420 may be similar to the backing layer or covering layer 220 described with reference to fig. 2B. In some embodiments, second backing layer 420 may be the same material as first backing layer 423. In other embodiments, second backing layer 420 may be a different material than first backing layer 423. In some embodiments, the tissue contacting layer, the first backing layer, the intermediate drape, and the second backing layer all have substantially the same perimeter size and shape as shown in fig. 4A-4C. In some embodiments, a spacer layer or transmission layer (not shown) may be provided as part of the upper wound dressing member 460. In some embodiments, a spacer layer may be positioned between the intermediate drape 422 and the absorbent layer 421, similar to the layered construction described with reference to fig. 2B. In some embodiments, the absorbing material 421 may be used without a spacer layer material. In some embodiments, the upper wound dressing member 460 may include multiple absorbent layers and/or multiple spacer layers.

The second backing layer 420 can include an aperture or opening 427. The fluid connector 440 may be disposed over an aperture or opening 427 in the second backing layer 420. The fluid connector 440 is similar to the fluid connector 110 described with reference to fig. 2A-2B. The fluid connector 440 may include an elongated catheter and an applicator 480. As shown in fig. 4C, the applicator 480 may be positioned over and sealed to an aperture or opening 427 in the second backing layer 420 for delivering negative pressure to the wound dressing 400.

Fig. 4C illustrates a cross-section of an embodiment of a negative pressure wound therapy system employing a lower wound dressing member comprising a foam layer capable of conforming to a patient, and an upper wound dressing member capable of absorbing and storing wound exudate. Reference numerals and similarly-named components in fig. 4C refer to the same or substantially similar components as those of fig. 2B, unless otherwise specified. In some embodiments, the port 440 can be disposed over an opening 427 in the second backing layer 420. The port may include a filter 414. In some embodiments, the negative pressure source can be in fluid communication with the port 440 and/or the opening 427 in the second backing layer. The negative pressure source can apply negative pressure through an opening or aperture 427 in the second backing layer.

Apertures

427, 452, 451 in the second backing layer 420, the intermediate layer 422, and the first backing layer 423 can provide fluid communication between the negative pressure source and the wound. In some embodiments, the absorber layer 421 can include vias 428 that extend through the absorber layer 421. In some embodiments, as shown in fig. 4C, the through-holes 428 may be aligned below the filter 414. In other embodiments, the through-hole 428 may be offset from the filter 414. In some embodiments, the components of the wound dressing may be held in alignment by a central adhesive.

In some embodiments, aperture 451 and aperture 452 may be positioned at a central portion of intermediate drape 422 and first backing layer 423, respectively, as shown in fig. 4A-4C. In some embodiments, aperture 451 and aperture 452 may be positioned in a corner, an edge, or in any portion of intermediate drape 422 and first backing layer 423, respectively. In some embodiments, the apertures or

openings

451, 452 may be rectangular openings or slits that form a channel when aligned and sealed to the aperture or opening 452. In some embodiments, the intermediate drape 422 and the first backing layer 423 may have two or more apertures or openings to provide fluid communication between the conformable manifold system 450 and the absorbent material of the wound dressing. In some embodiments,

apertures

451 and 452 may be positioned offset from filter 414 and through-hole 428 as shown in fig. 4C. In other embodiments,

apertures

451 and 452 may be aligned below filter 414 and through-hole 428.

The wound dressing system includes a lower wound dressing member having a conformable manifold for conforming to a patient, the conformable manifold in communication with an absorbent material of an upper wound dressing member for absorbing and storing wound exudate. In some embodiments, an absorbent dressing member as described above may be stiffer or more rigid than a foam or transmission layer that may be used as a dressing member. Thus, in some embodiments, the rigid (stiffer) components of the dressing may be separate from the foam or lower barrier layer as described herein.

The structures described herein may allow the dressing to be able to conform to contoured areas of a patient's body while also allowing a stiffer absorbent dressing component to be incorporated into the upper wound dressing component 460 of the wound dressing. In some embodiments, when a conformable manifold system is used, the upper wound dressing member can fold like a sea anemone when negative pressure is applied, as further described herein. In some embodiments, the foam may be compressible to produce good molding and no embossing. Additionally, in some embodiments, the lower wound dressing member may provide a more complete and effective seal for the patient's body.

Fig. 5A-5G illustrate an embodiment of a negative pressure wound therapy system that employs a lower wound dressing member that includes a foam layer that can conform to a patient, and an upper wound dressing member that can absorb and store wound exudate. Fig. 5A shows a top view of a wound dressing as described herein. Fig. 5B illustrates an embodiment of the wound dressing in which the upper wound dressing member 460 is lifted away from the lower wound dressing member 450. As shown in fig. 5B, the lower wound dressing component includes a foam or lower spacer layer 424 enclosed within a first backing layer 423 and a lower wound contact layer (not shown). The absorbent material 421 is shown enclosed within the intermediate drape 422 and the second backing layer 420, forming an upper wound dressing component 460 over the lower wound dressing component 450.

Fig. 5C illustrates an embodiment of a wound dressing in which the lower wound dressing member is positioned on a contoured portion of a patient's body. As shown in fig. 5C, the lower wound dressing member 450 is placed over the contoured body portion of the patient and sealed to the skin. In some embodiments, the lower wound dressing member 450 will surround and conform to the body while the upper wound dressing member 460 bends and conforms less to the body area. In some embodiments, the first backing layer 423 and/or the wound contact layer 425 may be flexible so as not to restrict movement or bending of the lower spacer layer 424 as it conforms to the contoured shape. In some embodiments, the first backing layer 423 and/or the wound contact layer 425 may have additional material so as not to limit the bending movement of the lower spacer layer 424 as it conforms to the contoured shape.

Fig. 5D-5F show embodiments of the wound dressing after application of negative pressure. As shown in fig. 5D-5F, the lower wound dressing member 450 is drawn down and conforms to the body part, and the upper wound dressing member 460 is folded and puckered. In some embodiments, the upper wound dressing member 460 may fold and suck down in a manner similar to the shape and movement of an anemone. For example, with application of negative pressure, the upper wound dressing component may be drawn inward and downward toward the connection point in the aperture in the intermediate drape and the first backing layer. As shown in fig. 5D-5F, the upper wound dressing member 460 may be folded inward from the central portion and may fold onto itself as the edges are pushed inward and upward. In some embodiments, the second backing layer 420 and/or the intermediate drape 422 may be sufficiently flexible to not restrict movement or bending of the absorbent component when inhaled, folded, and/or crumpled. In some embodiments, the second backing layer 420 and/or the intermediate drape 422 may have additional material so as not to limit the bending movement of the absorbent member when it is absorbed, folded, and/or crumpled.

Fig. 5G illustrates an embodiment of a negative pressure wound therapy system that employs a lower wound dressing member that includes a foam layer that can conform to a patient, and an upper wound dressing member that can absorb and store wound exudate. In some embodiments, as shown in fig. 5G, the foam or spacer layer 424 of the lower wound dressing component may have a larger diameter and extend outward beyond the perimeter of the absorbent material 421. As shown in fig. 5G, the foam or lower spacing layer 424 may have a larger perimeter dimension than the absorbent layer 421 and/or the spacing layer of the absorbent dressing component on top of it. In some embodiments, this may prevent pad edge embossing. In some embodiments, the circumference of the lower isolation layer 424 may be about 5mm larger than the absorbent layer 421.

In some embodiments, the lower spacer or foam layer 424' may include slits or cuts 499 in the foam material, as shown in FIGS. 6A-6B. Slit or cut modifications to the foam or spacer material 424' may further enhance the ability of the material to conform to contoured shapes or body parts. Fig. 6A-6B illustrate an embodiment of a foam layer 424' for use in a negative pressure wound therapy system. When foam slits or cuts 499 are utilized, the foam material may be stiffer and the slits will still allow the foam or spacer layer material 424 'to conform to the contours of the patient's body. The slits or cuts 499 may comprise one or more slits or cuts that are horizontal (extending parallel to the length of the foam or spacer material 424'). The slits or cuts 499 may comprise one or more slits or cuts that are vertical (extending perpendicular to the length of the foam or spacer material 424'). In some embodiments, as shown in FIGS. 6A-6B, slits or cuts 499 may include one or more slits or cuts that are horizontal, and one or more slits or cuts that are vertical. Providing slits or cuts extending in two different directions, the foam or spacer material 424 'may fit and surround the contoured body area of the patient along both the length and width of the foam or spacer material 424'. In some embodiments, the slits or cuts 499 may be distributed throughout the foam or spacer material 424'. In other embodiments, the slits or cuts may be localized to a portion of the foam or spacer material 424'. For example, the slits or cuts may be in the central portion only and/or on the edge portions only. In some embodiments, the slits or cuts 499 may be provided in a pattern and/or distributed evenly over the foam or spacer material 424'. In some embodiments, the slits or cuts 499 may be randomly distributed or provided on the foam or spacer layer 424'.

All of the features disclosed in this specification (including any accompanying illustrations, claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The present disclosure is not limited to the details of any of the foregoing embodiments. The disclosure extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Various modifications to the embodiments described in this disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and features disclosed herein. Certain embodiments of the present disclosure are encompassed by the claims set forth below or presented in the future.

Claims

1. A negative pressure wound therapy apparatus comprising:

a wound dressing comprising a first dressing portion and a second dressing portion overlying the first dressing portion,

the first dressing portion comprises:

a tissue contact layer configured to be positioned in contact with a wound and/or skin surrounding a wound, wherein the tissue contact layer comprises a first boundary portion at a perimeter of the tissue contact layer;

a first spacer layer; and

a first backing layer comprising first apertures, wherein the first backing layer comprises a second border portion at a perimeter of the first backing layer, wherein the spacing layer is positioned between the tissue-contacting layer and the first backing layer, and the first border portion of the tissue-contacting layer is sealed to the second border portion of the first backing layer; and is

The second dressing portion comprises:

an intermediate drape comprising a second aperture, wherein the intermediate drape comprises a third boundary portion at a perimeter of the intermediate drape;

an absorber layer, and

a second backing layer comprising a fourth boundary portion at a perimeter of the second backing layer, wherein the absorbent layer is positioned between the intermediate drape and the second backing layer, and the third boundary portion of the intermediate drape is sealed to the fourth boundary portion of the second backing layer; and is

Wherein the second dressing portion is attached to the first dressing portion such that the first aperture and the second aperture are fluidly connected, and wherein the second boundary portion of the first backing layer is unattached to the third boundary portion of the intermediate drape.

2. The negative pressure wound therapy apparatus of claim 1, further comprising a suction port attached to the second backing layer over a third aperture in the second backing layer.

3. The negative pressure wound therapy apparatus of claim 2, further comprising a filter configured to prevent or inhibit liquid from entering the suction port.

4. The negative pressure wound therapy apparatus of any one of claims 2-3, further comprising a negative pressure source configured to apply negative pressure through the third aperture in the second backing layer, wherein the first, second, and third apertures are in fluid communication with one another and are configured to provide fluid communication between the negative pressure source and the wound.

5. The negative pressure wound therapy apparatus of any of the preceding claims, wherein the first spacer layer comprises foam.

6. The negative pressure wound therapy apparatus of any one of the preceding claims, wherein the absorbent layer comprises a super absorbent material.

7. The negative pressure wound therapy apparatus of any one of the preceding claims, further comprising a second spacer layer, wherein the second spacer layer is positioned between the absorbent layer and the intermediate drape.

8. The negative pressure wound therapy apparatus of claim 7, wherein the second spacer layer comprises a 3D fabric.

9. The negative pressure wound therapy apparatus of any one of the preceding claims, wherein the first backing layer comprises a flexible material or an additional material configured to allow the first backing material to bend.

10. The negative pressure wound therapy apparatus of any of the preceding claims, wherein the first spacer layer comprises a plurality of slits.

11. The negative pressure wound therapy apparatus of any one of the preceding claims, further comprising a through-hole extending through the absorbent layer.

12. The negative pressure wound therapy apparatus of claim 11, wherein the through-hole is aligned below a suction port attached to the second backing layer.

13. The negative pressure wound therapy apparatus of any one of the preceding claims, wherein the second backing layer comprises a moisture vapor permeable material.

14. The negative pressure wound therapy apparatus of any of the preceding claims, wherein the tissue contact layer, the first backing layer, the intermediate drape, and the second backing layer all have substantially the same perimeter size and shape.

15. The negative pressure wound therapy apparatus of any one of the preceding claims, wherein the first backing layer is configured to attach to the intermediate drape at an area around the first aperture and an area around the second aperture.

16. The negative pressure wound therapy apparatus of any one of the preceding claims, wherein the first spacer layer has a smaller perimeter dimension than the tissue contact layer and the first backing layer.

17. The negative pressure wound therapy apparatus of any of the preceding claims, wherein the first spacer layer has a rectangular shape, a rounded rectangular shape, a racetrack shape, an oval shape, a circular shape, a triangular shape, or an irregular shape.

18. The negative pressure wound therapy apparatus of any one of claims 2-17, wherein the third aperture in the second backing layer is located at a central region of the second backing layer.

19. The negative pressure wound therapy apparatus of any one of claims 2-17, wherein the third aperture in the second backing layer is located at an edge region of the second backing layer.

20. The negative pressure wound therapy apparatus of any one of claims 2-17, wherein the third aperture in the second backing layer is located at a corner of the second backing layer.

21. The negative pressure wound therapy apparatus of any one of the preceding claims, wherein the tissue contact layer extends across the entire area beneath the first backing layer.

22. The negative pressure wound therapy apparatus of any one of the preceding claims, wherein the tissue contact layer comprises apertures, pores, or perforations to enable fluid flow through the tissue contact layer.

23. A method of treating a wound with a negative pressure wound therapy device, comprising:

positioning a wound dressing over the wound, the wound dressing comprising:

a first portion and a second portion, the first portion comprising:

a first spacer layer; and

The second dressing portion includes:

an absorber layer, and

a second backing layer comprising a fourth boundary portion at a perimeter of the second backing layer, wherein the absorbent layer is positioned between the intermediate drape and the second backing layer, and the third boundary portion of the intermediate drape is sealed to the fourth boundary portion of the second backing layer;

wherein the second dressing portion is attached to the first dressing portion such that the first aperture and the second aperture are fluidly connected, and wherein the second boundary portion of the first backing layer is unattached to the third boundary portion of the intermediate drape; and

applying negative pressure through a third aperture in the cover layer, wherein the first aperture, the second aperture, and the third aperture provide fluid communication between a source of negative pressure and the wound.